Book Image

C++20 STL Cookbook

By : Bill Weinman
Book Image

C++20 STL Cookbook

By: Bill Weinman

Overview of this book

Fast, efficient, and flexible, the C++ programming language has come a long way and is used in every area of the industry to solve many problems. The latest version C++20 will see programmers change the way they code as it brings a whole array of features enabling the quick deployment of applications. This book will get you up and running with using the STL in the best way possible. Beginning with new language features in C++20, this book will help you understand the language's mechanics and library features and offer insights into how they work. Unlike other books, the C++20 STL Cookbook takes an implementation-specific, problem-solution approach that will help you overcome hurdles quickly. You'll learn core STL concepts, such as containers, algorithms, utility classes, lambda expressions, iterators, and more, while working on real-world recipes. This book is a reference guide for using the C++ STL with its latest capabilities and exploring the cutting-edge features in functional programming and lambda expressions. By the end of the book C++20 book, you'll be able to leverage the latest C++ features and save time and effort while solving tasks elegantly using the STL.
Table of Contents (13 chapters)

Use uniform erasure functions to delete items from a container

Before C++20, the erase-remove idiom was commonly used to efficiently delete elements from an STL container. This was a little cumbersome, but not a great burden. It was common to use a function like this for the task:

template<typename Tc, typename Tv>
void remove_value(Tc & c, const Tv v) {
    auto remove_it = std::remove(c.begin(), c.end(), v);
    c.erase(remove_it, c.end());
}

The std::remove() function is from the <algorithms> header. std::remove() searches for the specified value and removes it by shifting elements forward from the end of the container. It does not change the size of the container. It returns an iterator past the end of the shifted range. We then call the container's erase() function to delete the remaining elements.

This two-step process is now reduced to one step with the new uniform erasure function:

std::erase(c, 5); ...